import org.openrdf.query.algebra.Union; //导入依赖的package包/类
/**
 * Transform a statement pattern according to OWL-2 subclass axiom.
 *
 * @param node the node to transform
 * @return list of nodes to visit next
 */
@Override
public List<QueryModelNode> apply(StatementPattern node) {
	List<QueryModelNode> next = newNextList();
	StatementPattern left = node.clone();
	// replace the object with the subclass
	StatementPattern right
			= new StatementPattern(
					node.getSubjectVar(),
					node.getPredicateVar(),
					new ConstVar(vf.createURI(ce1)),
					node.getContextVar());
	node.replaceWith(
			new Union(left, right));
	next.add(left);
	next.add(right);
	return next;
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
/**
 * Transform a statement pattern according to OWL-2 subproperty axiom.
 *
 * @param node the node to transform
 * @return list of nodes to visit next
 */
@Override
public List<QueryModelNode> apply(StatementPattern node) {
	List<QueryModelNode> next = newNextList();
	StatementPattern left = node.clone();
	// replace the predicate with the subproperty
	StatementPattern right
			= new StatementPattern(
					node.getSubjectVar(),
					new ConstVar(vf.createURI(op1)),
					node.getObjectVar(),
					node.getContextVar());
	node.replaceWith(
			new Union(left, right));
	next.add(left);
	next.add(right);
	return next;
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
/**
 * Transform a statement pattern according to OWL-2 inverse properties
 * axiom.
 *
 * @param node the node to transform
 * @return list of nodes to visit next
 */
@Override
public List<QueryModelNode> apply(StatementPattern node) {
	List<QueryModelNode> next = newNextList();
	Var s = node.getSubjectVar();
	Var p = node.getPredicateVar();
	Var o = node.getObjectVar();
	Var c = node.getContextVar();
	URI uri = (URI) p.getValue();
	String op = uri.stringValue();
	Var p2;
	// check if need to replace with op1 or op2
	if (op.equals(op1)) {
		p2 = new ConstVar(vf.createURI(op2));
	} else {
		p2 = new ConstVar(vf.createURI(op1));
	}
	StatementPattern left = node.clone();
	// switch subject and object and replace predicate
	StatementPattern right = new StatementPattern(o, p2, s, c);
	node.replaceWith(new Union(left, right));
	next.add(left);
	next.add(right);
	return next;
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Test
public void testReflexiveProperty() throws Exception {
    // Define a reflexive property
    final InferenceEngine inferenceEngine = mock(InferenceEngine.class);
    when(inferenceEngine.isReflexiveProperty(HAS_FAMILY)).thenReturn(true);
    // Construct a query, then visit it
    final StatementPattern sp = new StatementPattern(new Var("s", ALICE), new Var("p", HAS_FAMILY), new Var("o"));
    final Projection query = new Projection(sp, new ProjectionElemList(new ProjectionElem("o", "member")));
    query.visit(new ReflexivePropertyVisitor(conf, inferenceEngine));
    // Expected structure after rewriting SP(:Alice :hasFamilyMember ?member):
    //
    // Union(
    //     originalSP(:Alice :hasFamilyMember ?member),
    //     ZeroLengthPath(:Alice, ?member)
    // )
    Assert.assertTrue(query.getArg() instanceof Union);
    final TupleExpr left = ((Union) query.getArg()).getLeftArg();
    final TupleExpr right = ((Union) query.getArg()).getRightArg();
    Assert.assertEquals(sp, left);
    Assert.assertTrue(right instanceof ZeroLengthPath);
    Assert.assertEquals(sp.getSubjectVar(), ((ZeroLengthPath) right).getSubjectVar());
    Assert.assertEquals(sp.getObjectVar(), ((ZeroLengthPath) right).getObjectVar());
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Test
public void testTypePattern() throws Exception {
    final InferenceEngine inferenceEngine = mock(InferenceEngine.class);
    final Set<URI> narcissistProps = new HashSet<>();
    narcissistProps.add(love);
    when(inferenceEngine.getHasSelfImplyingType(narcissist)).thenReturn(narcissistProps);
    final Var subj = new Var("s");
    final Var obj = new Var("o", narcissist);
    obj.setConstant(true);
    final Var pred = new Var("p", RDF.TYPE);
    pred.setConstant(true);

    final Projection query = new Projection(new StatementPattern(subj, pred, obj),
            new ProjectionElemList(new ProjectionElem("s", "subject")));
    query.visit(new HasSelfVisitor(conf, inferenceEngine));

    Assert.assertTrue(query.getArg() instanceof Union);
    final Union union = (Union) query.getArg();
    Assert.assertTrue(union.getRightArg() instanceof StatementPattern);
    Assert.assertTrue(union.getLeftArg() instanceof StatementPattern);
    final StatementPattern expectedLeft = new StatementPattern(subj, pred, obj);
    final StatementPattern expectedRight = new StatementPattern(subj, new Var("urn:love", love), subj);
    Assert.assertEquals(expectedLeft, union.getLeftArg());
    Assert.assertEquals(expectedRight, union.getRightArg());
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
public void meet(final Union union) {
    boolean filterMoved = false;
    if (Sets.intersection(union.getRightArg().getBindingNames(), filterVars).size() > 0) {
        relocate(filter, union.getRightArg());
        filterMoved = true;
    }
 
    if (Sets.intersection(union.getLeftArg().getBindingNames(), filterVars).size() > 0) {
        if (filterMoved) {
            final Filter clone = new Filter(filter.getArg(), filter.getCondition().clone());
            relocate(clone, union.getLeftArg());
        } else {
            relocate(filter, union.getLeftArg());
        }
    }
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
public void meet(final Union n) {
    final TupleExpr l = n.getLeftArg();
    final TupleExpr r = n.getRightArg();
    final ZeroLengthPath p = l instanceof ZeroLengthPath ? (ZeroLengthPath) l
            : r instanceof ZeroLengthPath ? (ZeroLengthPath) r : null;
    if (p == null) {
        emit(l, !(l instanceof Union)).emit(" UNION ").emit(r, !(r instanceof Union));
    } else {
        final Var s = p.getSubjectVar();
        final Var o = p.getObjectVar();
        final Var c = p.getContextVar();
        if (c != null) {
            emit("GRAPH ").emit(c).emit(" ").openBrace();
        }
        emit(s).emit(" ").emitPropertyPath(n, s, o).emit(" ").emit(o);
        if (c != null) {
            closeBrace();
        }
    }
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
/**
 * Transform a statement pattern to infer triples for a predicate variable.
 * 
 * @param node the node to transform
 * @return list of nodes to visit next
 */
@Override
public List<QueryModelNode> apply(StatementPattern node) {
	List<QueryModelNode> next = newNextList();
	StatementPattern left = node.clone();
	next.add(left);
	TupleExpr right = assignPredicates(predicates, node.clone(), next);
	node.replaceWith(new Union(left, right));
	return next;
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
/**
 * Transform a statement pattern according to OWL-2 property chain
 * axiom.
 * 
 * @param node the node to transform
 * @return list of nodes to visit next
 */
@Override
public List<QueryModelNode> apply(StatementPattern node) {
	List<QueryModelNode> next = newNextList();
	Var s = node.getSubjectVar();
	Var o = node.getObjectVar();
	Var c = node.getContextVar();
	TupleExpr left  = node.clone();
	TupleExpr right = getChain(s, o, c);
	node.replaceWith(new Union(left, right));
	next.add(left);
	next.add(right);
	return next;
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
protected void meetSP(StatementPattern node) throws Exception {
    StatementPattern sp = node.clone();
    final Var predVar = sp.getPredicateVar();

    URI pred = (URI) predVar.getValue();
    String predNamespace = pred.getNamespace();

    final Var objVar = sp.getObjectVar();
    final Var cntxtVar = sp.getContextVar();
    if (objVar != null &&
            !RDF.NAMESPACE.equals(predNamespace) &&
            !SESAME.NAMESPACE.equals(predNamespace) &&
            !RDFS.NAMESPACE.equals(predNamespace)
            && !EXPANDED.equals(cntxtVar)) {
        /**
         *
         * { ?a ?pred ?b .}\n" +
         "       UNION " +
         "      { ?b ?pred ?a }
         */

        URI predUri = (URI) predVar.getValue();
        URI invPropUri = inferenceEngine.findInverseOf(predUri);
        if (invPropUri != null) {
            Var subjVar = sp.getSubjectVar();
            Union union = new InferUnion();
            union.setLeftArg(sp);
            union.setRightArg(new StatementPattern(objVar, new Var(predVar.getName(), invPropUri), subjVar, cntxtVar));
            node.replaceWith(union);
        }
    }
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
protected void meetSP(final StatementPattern node) throws Exception {
    final StatementPattern currentNode = node.clone();
    final Var subVar = node.getSubjectVar();
    final Var predVar = node.getPredicateVar();
    final Var objVar = node.getObjectVar();
    final Var conVar = node.getContextVar();
    if (predVar != null && objVar != null && objVar.getValue() != null && RDF.TYPE.equals(predVar.getValue()) && !EXPANDED.equals(conVar)) {
        final List<Set<Resource>> intersections = inferenceEngine.getIntersectionsImplying((URI) objVar.getValue());
        if (intersections != null && !intersections.isEmpty()) {
            final List<TupleExpr> joins = new ArrayList<>();
            for (final Set<Resource> intersection : intersections) {
                final Set<Resource> sortedIntersection = new TreeSet<>(new ResourceComparator());
                sortedIntersection.addAll(intersection);

                // Create a join tree of all statement patterns in the
                // current intersection.
                final TupleExpr joinTree = createJoinTree(new ArrayList<>(sortedIntersection), subVar, conVar);
                if (joinTree != null) {
                    joins.add(joinTree);
                }
            }

            if (!joins.isEmpty()) {
                // Combine all the intersection join trees for the type
                // together into a union tree.  This will be a join tree if
                // only one intersection exists.
                final TupleExpr unionTree = createUnionTree(joins);
                // Union the above union tree of intersections with the
                // original node.
                final Union union = new InferUnion(unionTree, currentNode);
                node.replaceWith(union);
                log.trace("Replacing node with inferred intersection union: " + union);
            }
        }
    }
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
protected void meetSP(StatementPattern node) throws Exception {
    StatementPattern sp = node.clone();

    final Var predVar = sp.getPredicateVar();
    URI pred = (URI) predVar.getValue();
    String predNamespace = pred.getNamespace();

    final Var objVar = sp.getObjectVar();
    final Var cntxtVar = sp.getContextVar();
    if (objVar != null &&
            !RDF.NAMESPACE.equals(predNamespace) &&
            !SESAME.NAMESPACE.equals(predNamespace) &&
            !RDFS.NAMESPACE.equals(predNamespace)
            && !EXPANDED.equals(cntxtVar)) {
        /**
         *
         * { ?a ?pred ?b .}\n" +
         "       UNION " +
         "      { ?b ?pred ?a }
         */

        URI symmPropUri = (URI) predVar.getValue();
        if(inferenceEngine.isSymmetricProperty(symmPropUri)) {
            Var subjVar = sp.getSubjectVar();
            Union union = new InferUnion();
            union.setLeftArg(sp);
            union.setRightArg(new StatementPattern(objVar, predVar, subjVar, cntxtVar));
            node.replaceWith(union);
        }
    }
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Test
public void testPropertyPattern_constantSubj() throws Exception {
    final InferenceEngine inferenceEngine = mock(InferenceEngine.class);
    final Set<Resource> loveTypes = new HashSet<>();
    loveTypes.add(narcissist);
    when(inferenceEngine.getHasSelfImplyingProperty(love)).thenReturn(loveTypes);
    final Var subj = new Var("s", self);
    subj.setConstant(true);
    final Var obj = new Var("o");
    final Var pred = new Var("p", love);
    pred.setConstant(true);

    final Projection query = new Projection(new StatementPattern(subj, pred, obj),
            new ProjectionElemList(new ProjectionElem("s", "subject")));
    query.visit(new HasSelfVisitor(conf, inferenceEngine));

    Assert.assertTrue(query.getArg() instanceof Union);
    final Union union = (Union) query.getArg();
    Assert.assertTrue(union.getRightArg() instanceof StatementPattern);
    Assert.assertTrue(union.getLeftArg() instanceof Extension);
    final StatementPattern expectedRight = new StatementPattern(subj, pred, obj);
    final Extension expectedLeft = new Extension(
            new StatementPattern(subj, new Var(RDF.TYPE.stringValue(), RDF.TYPE), new Var("urn:Narcissist", narcissist)),
            new ExtensionElem(subj, "o"));
    Assert.assertEquals(expectedLeft, union.getLeftArg());
    Assert.assertEquals(expectedRight, union.getRightArg());
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Test
public void testPropertyPattern_constantObj() throws Exception {
    final InferenceEngine inferenceEngine = mock(InferenceEngine.class);
    final Set<Resource> loveTypes = new HashSet<>();
    loveTypes.add(narcissist);
    when(inferenceEngine.getHasSelfImplyingProperty(love)).thenReturn(loveTypes);
    final Var subj = new Var("s");
    final Var obj = new Var("o", self);
    obj.setConstant(true);
    final Var pred = new Var("p", love);
    pred.setConstant(true);

    final Projection query = new Projection(new StatementPattern(subj, pred, obj),
            new ProjectionElemList(new ProjectionElem("s", "subject")));
    query.visit(new HasSelfVisitor(conf, inferenceEngine));

    Assert.assertTrue(query.getArg() instanceof Union);
    final Union union = (Union) query.getArg();
    Assert.assertTrue(union.getRightArg() instanceof StatementPattern);
    Assert.assertTrue(union.getLeftArg() instanceof Extension);
    final StatementPattern expectedRight = new StatementPattern(subj, pred, obj);
    final Extension expectedLeft = new Extension(
            new StatementPattern(obj, new Var(RDF.TYPE.stringValue(), RDF.TYPE), new Var("urn:Narcissist", narcissist)),
            new ExtensionElem(obj, "s"));
    Assert.assertEquals(expectedLeft, union.getLeftArg());
    Assert.assertEquals(expectedRight, union.getRightArg());
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
public void meetNode(final QueryModelNode node) {
	if (!(node instanceof Join || node instanceof LeftJoin
			|| node instanceof StatementPattern || node instanceof Var
			|| node instanceof Union || node instanceof Filter || node instanceof Projection)) {
		isValid = false;
		return;
	}
	super.meetNode(node);
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
public void meet(Union node) throws RuntimeException {
	setSeen(node);
	super.meet(node);
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
public void meet(Union node) throws RuntimeException {
	check(node);
	super.meet(node);
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
    public void meet(Union node) throws Exception {
//        if (!(node instanceof InferUnion))
        super.meet(node);
    }
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Test
public void testSomeValuesFrom() throws Exception {
    // Configure a mock instance engine with an ontology:
    final InferenceEngine inferenceEngine = mock(InferenceEngine.class);
    Map<Resource, Set<URI>> personSVF = new HashMap<>();
    personSVF.put(gradCourse, Sets.newHashSet(takesCourse));
    personSVF.put(course, Sets.newHashSet(takesCourse));
    personSVF.put(department, Sets.newHashSet(headOf));
    personSVF.put(organization, Sets.newHashSet(worksFor, headOf));
    when(inferenceEngine.getSomeValuesFromByRestrictionType(person)).thenReturn(personSVF);
    // Query for a specific type and rewrite using the visitor:
    StatementPattern originalSP = new StatementPattern(new Var("s"), new Var("p", RDF.TYPE), new Var("o", person));
    final Projection query = new Projection(originalSP, new ProjectionElemList(new ProjectionElem("s", "subject")));
    query.visit(new SomeValuesFromVisitor(conf, inferenceEngine));
    // Expected structure: a union of two elements: one is equal to the original statement
    // pattern, and the other one joins a list of predicate/value type combinations
    // with another join querying for any nodes who are the subject of a triple with that
    // predicate and with an object of that type.
    //
    // Union(
    //     SP(?node a :impliedType),
    //     Join(
    //         FSP(<?property someValuesFrom ?valueType> {
    //             takesCourse/Course;
    //             takesCourse/GraduateCourse;
    //             headOf/Department;
    //             headOf/Organization;
    //             worksFor/Organization;
    //         }),
    //         Join(
    //             SP(_:object a ?valueType),
    //             SP(?node ?property _:object)
    //         )
    //     )
    Assert.assertTrue(query.getArg() instanceof Union);
    TupleExpr left = ((Union) query.getArg()).getLeftArg();
    TupleExpr right = ((Union) query.getArg()).getRightArg();
    Assert.assertEquals(originalSP, left);
    Assert.assertTrue(right instanceof Join);
    final Join join = (Join) right;
    Assert.assertTrue(join.getLeftArg() instanceof FixedStatementPattern);
    Assert.assertTrue(join.getRightArg() instanceof Join);
    FixedStatementPattern fsp = (FixedStatementPattern) join.getLeftArg();
    left = ((Join) join.getRightArg()).getLeftArg();
    right = ((Join) join.getRightArg()).getRightArg();
    Assert.assertTrue(left instanceof StatementPattern);
    Assert.assertTrue(right instanceof StatementPattern);
    // Verify expected predicate/type pairs
    Assert.assertTrue(fsp.statements.contains(new NullableStatementImpl(takesCourse, OWL.SOMEVALUESFROM, course)));
    Assert.assertTrue(fsp.statements.contains(new NullableStatementImpl(takesCourse, OWL.SOMEVALUESFROM, gradCourse)));
    Assert.assertTrue(fsp.statements.contains(new NullableStatementImpl(headOf, OWL.SOMEVALUESFROM, department)));
    Assert.assertTrue(fsp.statements.contains(new NullableStatementImpl(headOf, OWL.SOMEVALUESFROM, organization)));
    Assert.assertTrue(fsp.statements.contains(new NullableStatementImpl(worksFor, OWL.SOMEVALUESFROM, organization)));
    Assert.assertEquals(5, fsp.statements.size());
    // Verify pattern for matching instances of each pair: a Join of <_:x rdf:type ?t> and
    // <?s ?p _:x> where p and t are the predicate/type pair and s is the original subject
    // variable.
    StatementPattern leftSP = (StatementPattern) left;
    StatementPattern rightSP = (StatementPattern) right;
    Assert.assertEquals(rightSP.getObjectVar(), leftSP.getSubjectVar());
    Assert.assertEquals(RDF.TYPE, leftSP.getPredicateVar().getValue());
    Assert.assertEquals(fsp.getObjectVar(), leftSP.getObjectVar());
    Assert.assertEquals(originalSP.getSubjectVar(), rightSP.getSubjectVar());
    Assert.assertEquals(fsp.getSubjectVar(), rightSP.getPredicateVar());
}
 

import org.openrdf.query.algebra.Union; //导入依赖的package包/类
@Override
public void meet(Union node) {
	nodes.add(node);
}